HIV Target Cells: How the Virus Attacks the Immune System

HIV primarily infects CD4+ T helper lymphocytes—white blood cells crucial for coordinating immune responses against pathogens.

Mechanism of Damage

1. HIV binds to CD4 receptor and co-receptors (CCR5/CXCR4) on T cells.
2. Viral RNA reverse-transcribes into DNA, integrates into host genome.
3. Infected cells produce new virions, then die or become dysfunctional.
4. Progressive CD4+ decline impairs immunity → opportunistic infections/cancers = AIDS.

Other Target Cells

• Macrophages, dendritic cells, microglial cells (CNS)
• Reservoirs in lymphoid tissue, gut-associated lymphoid tissue (GALT)

Clinical Significance

• CD4 count monitors disease stage and treatment urgency.
• ART suppresses viral replication, preserves CD4 cells, prevents transmission (U=U).
• Early treatment improves long-term outcomes dramatically.

Understanding cellular tropism guides drug development (entry inhibitors, latency-reversing agents) and cure research.